Re: Syntax question

I have no idea why I am getting messages from this forum.  Please get me 
off this list.

Les Morgan

Growth House, Inc.

http://www.growthhouse.org

http://www.twitter.com/lesmorgan

415-863-3045 

"You must be the change you wish to see in the world." 

-- Mahatma Gandhi

-------- Original Message --------
> From: "Cameron Ross" <[email protected]>
> Sent: Thursday, March 04, 2010 10:55 AM
> To: "Thomas Russ" <[email protected]>
> Subject: Re: [PowerLoom Forum] Syntax question
> 
> Thanks Thomas,
> 
> Based on your response I could probably infer what the following mean as
> well.  However, perhaps you could provide a brief synopsis for precision 
and
> clarity.
> 
> :<=
> :=>
> :<<=
> :<=>
> :<=>>
> :<<=>
> :<<=>>
> 
> Thanks much,
> Cameron.
> 
> 
> On Wed, Mar 3, 2010 at 2:15 PM, Thomas Russ <[email protected]> wrote:
> 
> >
> > On Mar 3, 2010, at 9:51 AM, Cameron Ross wrote:
> >
> >  Hi,
> >>
> >> Its not readily apparent from the PowerLoom documentation how to 
interpret
> >> :=>>.  Enlightenment would be very much appreciated.
> >>
> >
> > The extra > on the arrow heads are used for inference direction 
control.
> >
> > Normally, with a rule like
> >
> >   (A ?x)  :=> (B ?x)
> >
> > PowerLoom is free to run this rule either in a forward direction or a
> > backward direction.  Running it forward means that if we assert (A i-1) 
then
> > we immediately conclude (B i-1).  Running backward means that if we 
are
> > trying to prove (B i-1) or find (B ?x) then we look to see if (A i-1) 
is
> > already known.
> >
> > When extra arrow heads are used, this tells PowerLoom the desired 
direction
> > of the rule, so that
> >
> >  (A ?x)  :=>>  (B ?x)
> >
> > will be run only in the forward direction.  This gives some additional
> > inference control and affects both what will be inferred as well as 
the
> > performance of the reasoner.
> >
> >
> >
> 
> 
> -- 
> Cameron Ross
> Kojeware Corporation
> 705-929-1492
> 
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